Process of making chlorine



UNITED STATES PATENT OFFICE,

ERNEST SOLVAY, OF BRUSSELS, BELGIUM, ASSIGNOR TO THE SIOLVAY PROCESS COMPANY, OF SYRACUSE, NEIV YORK.

PROCESS OF MAKING CHLORINE.

SPECIFICATION forming part of Letters Patent No. 420,837, dated February 4, 1890. Application led February 14., 1889. Serial No. 299,918. (No model.) Patented in Belgium January 5, 1888, No. 82,050.

` To all whom t may concern:

Be it known that I, ERNEST SOLVAY, of Brussels, Belgium, have invented new and V useful Improvements in the Process of Evolving Chlorine, of which the following, takenin connection with the accompanying drawings, is a full, clear, and exact description.

My invention relates to improvements in the art of producing or evolving chlorine, (for which I have received Belgian Patent No. 82,050, dated January 5, 1888,) and has for its object a simple and effective manner of producing chlorine at a minimum cost of expense; and to this end it consists, essentially, in first calcining in a suitable furnace the clay to be mixed with the chlorine, then placing the calcined clay mixed with calcium chloride or other chloride into a high tower, having tuyeres leading thereinto about midway the height thereof, and forcing a blast of air upward from the bottom of the furnace or tower, all as hereinafter more fully described, and pointed out in the claims. Y

In describing my invention reference is had to the accompanying drawings, forming a part of this specification, in which like letters indicate corresponding parts in all the views.

Figure 1 is a vertical section of the tower used for decomposing the calcium chloride mixed with the calcined clay; and Fig. 2 is a horizontal section'of said furnace, taken on line w fr, Fig. l.

l have discovered that mixtures of calcium chloride and a siliciou's claydike substance give better results than a purely silicious base when decomposed for the purpose of producing chlorine gas. I have also observed that it is impossible to dry such a mixture up to the point of causing it to lose all its water without disengaging hydrochloric acid.

As there certainly is an advantagein reducing the quantity of hydrochloric acid formed at the same time with the chlorine, I calcine the silicious clay iirst separately, so as to drive off the water which it contains and to obtain a decomposing material, which has at t-he same time vthe advantages of silicious and of clay-like materials. This calcination can be accomplished by putting the clay, in the form of small bricks, into an appropriate furnace and afterward reducing it to powder. l g

Since there are various forms of furnaces which would be suitable for the calcination of the clay, it is unnecessary in my invention to illustrate or describe any particular kind, it being merely necessary to state that before its mixture with the calcium chloride the clay is calcined by any suitable furnace and is afterward reduced to powder by any of the well-known means.

In the previous manufacture of chlorine it has been customary 'to so form the furnaces for decomposing the material containing' chlorine and evolving the same therefrom'as to exclude from the field of reaction the combustible or carbonated gases. Chlorine has a strong affinity for carbonio oxide, forming therewith oxychloride of carbon or carbonyl chloride, from which the chlorine cannot be recovered in its active state. Vith this fact in view it has been customary to decompose the chlorine-containing material by means of furnaces heated from the outside, thus preventing the entrance of carbonio oxide and the consequent forming of oxychloride or carbon. This process of evolving chlorine by heating from the outside necessitates the use of a great amount of fuel and greatly adds to the cost of production.

By means of the furnace illustrated in the drawings and described and claimed in my apparatus application of even date herewith I introduce the carbonio oxide directly into the decomposing-chamber, but by the peculiar arrangement of the parts of the same prevent the forming of oxychloride of carbon gas.

Arepresen ts the decomposing-furnace, consisting of a high tower having a thick envel. ope of non-conducting material B, preventing radiation therefrom.

In the upper part of the furnaceAis an opening A', having a removableicoyer or cap, and into this opening a mixtureof calcium chloride and calcined silicious clay isinserted until the tower is filled.

.In the lower part of the furnace I provide the opening A2, into which the pipe C discharges and forces a current of air into the lower part of the furnace, from whence it constantly ascends. v

Interposed between the openings A and A2, about midway the height of the furnace, I provide apertur'es or tuyeres T, through which a crown of pipes E discharge the fuel, preferably carbonio oxide. The pipes E are connected by a suitable main or connecting pipe D to the discharge G of the furnace G. Coal or other fuel is placed in the furnace G, and the fire is so regulated that an abundance of carbonio oxide is produced and conducted from the flue or discharge G of the furnace G to the main D, whence it is inserted into the midst of the material in the furnace A by means of the pipes E, discharging through the tuyeres T. The air inserted from the bottom of the furnace A brings about the combustion of the carbonio oxide, and is supplied in suicient quantities to combine With the calcium chloride mixed with the silicious clay-like substance and to produce the reaction CaClQ-i-AlSOpa-HO: AlgO-CaSiO-i-SClz. The combustion of the carbonio oxide soon heats to a white heat the material on a level with the tuyeres forming the combustion-zone of the furnace. This zone extends only a short distance, and immediately above the same is the decomposingzone, in which the material is heated to ared heat and is thoroughly decomposed before its contact with the carbonic oxide in the combustion-zone, thus preventing the formation of oxychloride of carbon.

The peculiar arrangement of the tuyeres and the manner of recovering the heat, as presently explained, bring about a perfect combustion of the carbonio-oxide gas, and the heat is snieiently intense to thoroughly decompose the material before its entrance into the combustion-zone and its consequent meeting with the fresh carbonic-oxide gas discharged through the tuyeres. The carbonic oxide uniting with an atom of oxygen of the introduced air forms carbonic anhy dride, which is discharged through the discharge-opening A* at the same time with the chloride gas; but as there is no affinity between the two gases they do not unite with each other and may be readily separated, as in my process application of forming chloride of lime of even date herewith. The gases produced would carry off a great share of heat were it not for the fact that the com b \lstion-zoue is about midway the height of the furnace A, and the weight of material presses down upon the gases and causes them to pass slowly therethrough and imy part theirheat to the material, which is substantially cold, thus preventing loss of heat. The material having been acted upon grad ually sinks to the bottom of the furnace,

whence it is readily removed by suitable openings AS, provided therein. Considerable loss of heat would accrue from t-he constant feeding downward of the decomposed material were it not that the current of cold air rising 'upward through the lower part of the furnace chlorine gas, and it will be understood that in place of the calcium chloride other chlorides which would combine with the silicon of the clay might be used, that the clay might be used without being first calcined, that the order of the steps of my process might be somewhat varied from that described, and that other changes might be made Without departing from the spirit of my invention. It will also be understood that I do not restrict my invention to the use of carbonio oxide, since other fuel could be used-as, for instance, other gases or air charged with combustible dust.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. The herein-described process for the decomposition of chlorides in the dry state, the same consisting in filling into the decomposingr apparatus a column of a mixture of a chloride and a silicious clay-1ike material, introducing' gas or combustible dust midway in the decomposing apparatus, and thus producing combustion within said apparatus, and then introducing a current of air into the lower part of said decomposing apparatus, substantially as described.

2. The herein-described process of decomposing chlorides in the dry state, the same consisting in calcining a silicious clay-like material, then mixing a chloride with said calcined silicious clay-like material, filling said mixture into a decomposing apparatus, inserting gas or combustible dust midway within said apparatus, and thus producing combustion within said apparatus, and finally introducing a current of air into the lower part of said decomposing apparatus, substantially as set forth.

In testimony whereof I have hereunto signed my name, in the presence of twoattesting witnesses, at the city of Brussels, Bclgium, this 15th day of September, 1833.

ERNEST SOLVAY. Witnesses:

G. HARRY, J. A, Fiias'rn-Nnorr.

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